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2023-04-06loop: LOOP_CONFIGURE: send uevents for partitionsAlyssa Ross1-9/+9
[ Upstream commit bb430b69422640891b0b8db762885730579a4145 ] LOOP_CONFIGURE is, as far as I understand it, supposed to be a way to combine LOOP_SET_FD and LOOP_SET_STATUS64 into a single syscall. When using LOOP_SET_FD+LOOP_SET_STATUS64, a single uevent would be sent for each partition found on the loop device after the second ioctl(), but when using LOOP_CONFIGURE, no such uevent was being sent. In the old setup, uevents are disabled for LOOP_SET_FD, but not for LOOP_SET_STATUS64. This makes sense, as it prevents uevents being sent for a partially configured device during LOOP_SET_FD - they're only sent at the end of LOOP_SET_STATUS64. But for LOOP_CONFIGURE, uevents were disabled for the entire operation, so that final notification was never issued. To fix this, reduce the critical section to exclude the loop_reread_partitions() call, which causes the uevents to be issued, to after uevents are re-enabled, matching the behaviour of the LOOP_SET_FD+LOOP_SET_STATUS64 combination. I noticed this because Busybox's losetup program recently changed from using LOOP_SET_FD+LOOP_SET_STATUS64 to LOOP_CONFIGURE, and this broke my setup, for which I want a notification from the kernel any time a new partition becomes available. Signed-off-by: Alyssa Ross <hi@alyssa.is> [hch: reduced the critical section] Signed-off-by: Christoph Hellwig <hch@lst.de> Fixes: 3448914e8cc5 ("loop: Add LOOP_CONFIGURE ioctl") Link: https://lore.kernel.org/r/20230320125430.55367-1-hch@lst.de Signed-off-by: Jens Axboe <axboe@kernel.dk> Signed-off-by: Sasha Levin <sashal@kernel.org>
2023-03-22loop: Fix use-after-free issuesBart Van Assche1-8/+17
[ Upstream commit 9b0cb770f5d7b1ff40bea7ca385438ee94570eec ] do_req_filebacked() calls blk_mq_complete_request() synchronously or asynchronously when using asynchronous I/O unless memory allocation fails. Hence, modify loop_handle_cmd() such that it does not dereference 'cmd' nor 'rq' after do_req_filebacked() finished unless we are sure that the request has not yet been completed. This patch fixes the following kernel crash: Unable to handle kernel NULL pointer dereference at virtual address 0000000000000054 Call trace: css_put.42938+0x1c/0x1ac loop_process_work+0xc8c/0xfd4 loop_rootcg_workfn+0x24/0x34 process_one_work+0x244/0x558 worker_thread+0x400/0x8fc kthread+0x16c/0x1e0 ret_from_fork+0x10/0x20 Cc: Christoph Hellwig <hch@lst.de> Cc: Ming Lei <ming.lei@redhat.com> Cc: Jan Kara <jack@suse.cz> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Dan Schatzberg <schatzberg.dan@gmail.com> Fixes: c74d40e8b5e2 ("loop: charge i/o to mem and blk cg") Fixes: bc07c10a3603 ("block: loop: support DIO & AIO") Signed-off-by: Bart Van Assche <bvanassche@acm.org> Reviewed-by: Ming Lei <ming.lei@redhat.com> Link: https://lore.kernel.org/r/20230314182155.80625-1-bvanassche@acm.org Signed-off-by: Jens Axboe <axboe@kernel.dk> Signed-off-by: Sasha Levin <sashal@kernel.org>
2023-03-11loop: loop_set_status_from_info() check before assignmentZhong Jinghua1-4/+4
[ Upstream commit 9f6ad5d533d1c71e51bdd06a5712c4fbc8768dfa ] In loop_set_status_from_info(), lo->lo_offset and lo->lo_sizelimit should be checked before reassignment, because if an overflow error occurs, the original correct value will be changed to the wrong value, and it will not be changed back. More, the original patch did not solve the problem, the value was set and ioctl returned an error, but the subsequent io used the value in the loop driver, which still caused an alarm: loop_handle_cmd do_req_filebacked loff_t pos = ((loff_t) blk_rq_pos(rq) << 9) + lo->lo_offset; lo_rw_aio cmd->iocb.ki_pos = pos Fixes: c490a0b5a4f3 ("loop: Check for overflow while configuring loop") Signed-off-by: Zhong Jinghua <zhongjinghua@huawei.com> Reviewed-by: Chaitanya Kulkarni <kch@nvidia.com> Link: https://lore.kernel.org/r/20230221095027.3656193-1-zhongjinghua@huaweicloud.com Signed-off-by: Jens Axboe <axboe@kernel.dk> Signed-off-by: Sasha Levin <sashal@kernel.org>
2023-02-09use less confusing names for iov_iter direction initializersAl Viro1-6/+6
[ Upstream commit de4eda9de2d957ef2d6a8365a01e26a435e958cb ] READ/WRITE proved to be actively confusing - the meanings are "data destination, as used with read(2)" and "data source, as used with write(2)", but people keep interpreting those as "we read data from it" and "we write data to it", i.e. exactly the wrong way. Call them ITER_DEST and ITER_SOURCE - at least that is harder to misinterpret... Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> Stable-dep-of: 6dd88fd59da8 ("vhost-scsi: unbreak any layout for response") Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-12-31loop: Fix the max_loop commandline argument treatment when it is set to 0Isaac J. Manjarres1-16/+12
commit 85c50197716c60fe57f411339c579462e563ac57 upstream. Currently, the max_loop commandline argument can be used to specify how many loop block devices are created at init time. If it is not specified on the commandline, CONFIG_BLK_DEV_LOOP_MIN_COUNT loop block devices will be created. The max_loop commandline argument can be used to override the value of CONFIG_BLK_DEV_LOOP_MIN_COUNT. However, when max_loop is set to 0 through the commandline, the current logic treats it as if it had not been set, and creates CONFIG_BLK_DEV_LOOP_MIN_COUNT devices anyway. Fix this by starting max_loop off as set to CONFIG_BLK_DEV_LOOP_MIN_COUNT. This preserves the intended behavior of creating CONFIG_BLK_DEV_LOOP_MIN_COUNT loop block devices if the max_loop commandline parameter is not specified, and allowing max_loop to be respected for all values, including 0. This allows environments that can create all of their required loop block devices on demand to not have to unnecessarily preallocate loop block devices. Fixes: 732850827450 ("remove artificial software max_loop limit") Cc: stable@vger.kernel.org Cc: Ken Chen <kenchen@google.com> Signed-off-by: Isaac J. Manjarres <isaacmanjarres@google.com> Link: https://lore.kernel.org/r/20221208212902.765781-1-isaacmanjarres@google.com Signed-off-by: Jens Axboe <axboe@kernel.dk> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-08-24loop: Check for overflow while configuring loopSiddh Raman Pant1-0/+5
The userspace can configure a loop using an ioctl call, wherein a configuration of type loop_config is passed (see lo_ioctl()'s case on line 1550 of drivers/block/loop.c). This proceeds to call loop_configure() which in turn calls loop_set_status_from_info() (see line 1050 of loop.c), passing &config->info which is of type loop_info64*. This function then sets the appropriate values, like the offset. loop_device has lo_offset of type loff_t (see line 52 of loop.c), which is typdef-chained to long long, whereas loop_info64 has lo_offset of type __u64 (see line 56 of include/uapi/linux/loop.h). The function directly copies offset from info to the device as follows (See line 980 of loop.c): lo->lo_offset = info->lo_offset; This results in an overflow, which triggers a warning in iomap_iter() due to a call to iomap_iter_done() which has: WARN_ON_ONCE(iter->iomap.offset > iter->pos); Thus, check for negative value during loop_set_status_from_info(). Bug report: https://syzkaller.appspot.com/bug?id=c620fe14aac810396d3c3edc9ad73848bf69a29e Reported-and-tested-by: syzbot+a8e049cd3abd342936b6@syzkaller.appspotmail.com Cc: stable@vger.kernel.org Reviewed-by: Matthew Wilcox (Oracle) <willy@infradead.org> Signed-off-by: Siddh Raman Pant <code@siddh.me> Reviewed-by: Christoph Hellwig <hch@lst.de> Link: https://lore.kernel.org/r/20220823160810.181275-1-code@siddh.me Signed-off-by: Jens Axboe <axboe@kernel.dk>
2022-06-28block: remove blk_cleanup_diskChristoph Hellwig1-1/+1
blk_cleanup_disk is nothing but a trivial wrapper for put_disk now, so remove it. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Hannes Reinecke <hare@suse.de> Link: https://lore.kernel.org/r/20220619060552.1850436-7-hch@lst.de Signed-off-by: Jens Axboe <axboe@kernel.dk>
2022-06-28block: simplify disk shutdownChristoph Hellwig1-1/+0
Set the queue dying flag and call blk_mq_exit_queue from del_gendisk for all disks that do not have separately allocated queues, and thus remove the need to call blk_cleanup_queue for them. Rename blk_cleanup_disk to blk_mq_destroy_queue to make it clear that this function is intended only for separately allocated blk-mq queues. This saves an extra queue freeze for devices without a separately allocated queue. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Hannes Reinecke <hare@suse.de> Link: https://lore.kernel.org/r/20220619060552.1850436-6-hch@lst.de Signed-off-by: Jens Axboe <axboe@kernel.dk>
2022-06-03Merge tag 'for-5.19/drivers-2022-06-02' of git://git.kernel.dk/linux-blockLinus Torvalds1-4/+4
Pull more block driver updates from Jens Axboe: "A collection of stragglers that were late on sending in their changes and just followup fixes. - NVMe fixes pull request via Christoph: - set controller enable bit in a separate write (Niklas Cassel) - disable namespace identifiers for the MAXIO MAP1001 (Christoph) - fix a comment typo (Julia Lawall)" - MD fixes pull request via Song: - Remove uses of bdevname (Christoph Hellwig) - Bug fixes (Guoqing Jiang, and Xiao Ni) - bcache fixes series (Coly) - null_blk zoned write fix (Damien) - nbd fixes (Yu, Zhang) - Fix for loop partition scanning (Christoph)" * tag 'for-5.19/drivers-2022-06-02' of git://git.kernel.dk/linux-block: (23 commits) block: null_blk: Fix null_zone_write() nvmet: fix typo in comment nvme: set controller enable bit in a separate write nvme-pci: disable namespace identifiers for the MAXIO MAP1001 bcache: avoid unnecessary soft lockup in kworker update_writeback_rate() nbd: use pr_err to output error message nbd: fix possible overflow on 'first_minor' in nbd_dev_add() nbd: fix io hung while disconnecting device nbd: don't clear 'NBD_CMD_INFLIGHT' flag if request is not completed nbd: fix race between nbd_alloc_config() and module removal nbd: call genl_unregister_family() first in nbd_cleanup() md: bcache: check the return value of kzalloc() in detached_dev_do_request() bcache: memset on stack variables in bch_btree_check() and bch_sectors_dirty_init() block, loop: support partitions without scanning bcache: avoid journal no-space deadlock by reserving 1 journal bucket bcache: remove incremental dirty sector counting for bch_sectors_dirty_init() bcache: improve multithreaded bch_sectors_dirty_init() bcache: improve multithreaded bch_btree_check() md: fix double free of io_acct_set bioset md: Don't set mddev private to NULL in raid0 pers->free ...
2022-05-27block, loop: support partitions without scanningChristoph Hellwig1-4/+4
Historically we did distinguish between a flag that surpressed partition scanning, and a combinations of the minors variable and another flag if any partitions were supported. This was generally confusing and doesn't make much sense, but some corner case uses of the loop driver actually do want to support manually added partitions on a device that does not actively scan for partitions. To make things worsee the loop driver also wants to dynamically toggle the scanning for partitions on a live gendisk, which makes the disk->flags updates non-atomic. Introduce a new GD_SUPPRESS_PART_SCAN bit in disk->state that disables just scanning for partitions, and toggle that instead of GENHD_FL_NO_PART in the loop driver. Fixes: 1ebe2e5f9d68 ("block: remove GENHD_FL_EXT_DEVT") Reported-by: Ming Lei <ming.lei@redhat.com> Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Ming Lei <ming.lei@redhat.com> Link: https://lore.kernel.org/r/20220527055806.1972352-1-hch@lst.de Signed-off-by: Jens Axboe <axboe@kernel.dk>
2022-05-26Merge tag 'mm-stable-2022-05-25' of ↵Linus Torvalds1-2/+2
git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm Pull MM updates from Andrew Morton: "Almost all of MM here. A few things are still getting finished off, reviewed, etc. - Yang Shi has improved the behaviour of khugepaged collapsing of readonly file-backed transparent hugepages. - Johannes Weiner has arranged for zswap memory use to be tracked and managed on a per-cgroup basis. - Munchun Song adds a /proc knob ("hugetlb_optimize_vmemmap") for runtime enablement of the recent huge page vmemmap optimization feature. - Baolin Wang contributes a series to fix some issues around hugetlb pagetable invalidation. - Zhenwei Pi has fixed some interactions between hwpoisoned pages and virtualization. - Tong Tiangen has enabled the use of the presently x86-only page_table_check debugging feature on arm64 and riscv. - David Vernet has done some fixup work on the memcg selftests. - Peter Xu has taught userfaultfd to handle write protection faults against shmem- and hugetlbfs-backed files. - More DAMON development from SeongJae Park - adding online tuning of the feature and support for monitoring of fixed virtual address ranges. Also easier discovery of which monitoring operations are available. - Nadav Amit has done some optimization of TLB flushing during mprotect(). - Neil Brown continues to labor away at improving our swap-over-NFS support. - David Hildenbrand has some fixes to anon page COWing versus get_user_pages(). - Peng Liu fixed some errors in the core hugetlb code. - Joao Martins has reduced the amount of memory consumed by device-dax's compound devmaps. - Some cleanups of the arch-specific pagemap code from Anshuman Khandual. - Muchun Song has found and fixed some errors in the TLB flushing of transparent hugepages. - Roman Gushchin has done more work on the memcg selftests. ... and, of course, many smaller fixes and cleanups. Notably, the customary million cleanup serieses from Miaohe Lin" * tag 'mm-stable-2022-05-25' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (381 commits) mm: kfence: use PAGE_ALIGNED helper selftests: vm: add the "settings" file with timeout variable selftests: vm: add "test_hmm.sh" to TEST_FILES selftests: vm: check numa_available() before operating "merge_across_nodes" in ksm_tests selftests: vm: add migration to the .gitignore selftests/vm/pkeys: fix typo in comment ksm: fix typo in comment selftests: vm: add process_mrelease tests Revert "mm/vmscan: never demote for memcg reclaim" mm/kfence: print disabling or re-enabling message include/trace/events/percpu.h: cleanup for "percpu: improve percpu_alloc_percpu event trace" include/trace/events/mmflags.h: cleanup for "tracing: incorrect gfp_t conversion" mm: fix a potential infinite loop in start_isolate_page_range() MAINTAINERS: add Muchun as co-maintainer for HugeTLB zram: fix Kconfig dependency warning mm/shmem: fix shmem folio swapoff hang cgroup: fix an error handling path in alloc_pagecache_max_30M() mm: damon: use HPAGE_PMD_SIZE tracing: incorrect isolate_mote_t cast in mm_vmscan_lru_isolate nodemask.h: fix compilation error with GCC12 ...
2022-05-24Merge tag 'for-5.19/drivers-2022-05-22' of git://git.kernel.dk/linux-blockLinus Torvalds1-199/+167
Pull block driver updates from Jens Axboe: "Here are the driver updates queued up for 5.19. This contains: - NVMe pull requests via Christoph: - tighten the PCI presence check (Stefan Roese) - fix a potential NULL pointer dereference in an error path (Kyle Miller Smith) - fix interpretation of the DMRSL field (Tom Yan) - relax the data transfer alignment (Keith Busch) - verbose error logging improvements (Max Gurtovoy, Chaitanya Kulkarni) - misc cleanups (Chaitanya Kulkarni, Christoph) - set non-mdts limits in nvme_scan_work (Chaitanya Kulkarni) - add support for TP4084 - Time-to-Ready Enhancements (Christoph) - MD pull request via Song: - Improve annotation in raid5 code, by Logan Gunthorpe - Support MD_BROKEN flag in raid-1/5/10, by Mariusz Tkaczyk - Other small fixes/cleanups - null_blk series making the configfs side much saner (Damien) - Various minor drbd cleanups and fixes (Haowen, Uladzislau, Jiapeng, Arnd, Cai) - Avoid using the system workqueue (and hence flushing it) in rnbd (Jack) - Avoid using the system workqueue (and hence flushing it) in aoe (Tetsuo) - Series fixing discard_alignment issues in drivers (Christoph) - Small series fixing drivers poking at disk->part0 for openers information (Christoph) - Series fixing deadlocks in loop (Christoph, Tetsuo) - Remove loop.h and add SPDX headers (Christoph) - Various fixes and cleanups (Julia, Xie, Yu)" * tag 'for-5.19/drivers-2022-05-22' of git://git.kernel.dk/linux-block: (72 commits) mtip32xx: fix typo in comment nvme: set non-mdts limits in nvme_scan_work nvme: add support for TP4084 - Time-to-Ready Enhancements nvme: split the enum used for various register constants nbd: Fix hung on disconnect request if socket is closed before nvme-fabrics: add a request timeout helper nvme-pci: harden drive presence detect in nvme_dev_disable() nvme-pci: fix a NULL pointer dereference in nvme_alloc_admin_tags nvme: mark internal passthru request RQF_QUIET nvme: remove unneeded include from constants file nvme: add missing status values to verbose logging nvme: set dma alignment to dword nvme: fix interpretation of DMRSL loop: remove most the top-of-file boilerplate comment from the UAPI header loop: remove most the top-of-file boilerplate comment loop: add a SPDX header loop: remove loop.h block: null_blk: Improve device creation with configfs block: null_blk: Cleanup messages block: null_blk: Cleanup device creation and deletion ...
2022-05-10loop: remove most the top-of-file boilerplate commentChristoph Hellwig1-47/+0
Remove the irrelevant changelogs and todo notes and just leave the SPDX marker and the copyright notice. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Chaitanya Kulkarni <kch@nvidia.com> Link: https://lore.kernel.org/r/20220419063303.583106-4-hch@lst.de Signed-off-by: Jens Axboe <axboe@kernel.dk>
2022-05-10loop: add a SPDX headerChristoph Hellwig1-2/+2
The copyright statement says: "Redistribution of this file is permitted under the GNU General Public License." and was added by Ted in 1993, at which point GPLv2 only was the default Linux license. Replace it with the usual GPLv2 only SPDX header. Signed-off-by: Christoph Hellwig <hch@lst.de> Link: https://lore.kernel.org/r/20220419063303.583106-3-hch@lst.de Signed-off-by: Jens Axboe <axboe@kernel.dk>
2022-05-10loop: remove loop.hChristoph Hellwig1-3/+54
Merge loop.h into loop.c as all the content is only used there. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Chaitanya Kulkarni <kch@nvidia.com> Link: https://lore.kernel.org/r/20220419063303.583106-2-hch@lst.de Signed-off-by: Jens Axboe <axboe@kernel.dk>
2022-05-10VFS: add FMODE_CAN_ODIRECT file flagNeilBrown1-2/+2
Currently various places test if direct IO is possible on a file by checking for the existence of the direct_IO address space operation. This is a poor choice, as the direct_IO operation may not be used - it is only used if the generic_file_*_iter functions are called for direct IO and some filesystems - particularly NFS - don't do this. Instead, introduce a new f_mode flag: FMODE_CAN_ODIRECT and change the various places to check this (avoiding pointer dereferences). do_dentry_open() will set this flag if ->direct_IO is present, so filesystems do not need to be changed. NFS *is* changed, to set the flag explicitly and discard the direct_IO entry in the address_space_operations for files. Other filesystems which currently use noop_direct_IO could usefully be changed to set this flag instead. Link: https://lkml.kernel.org/r/164859778128.29473.15189737957277399416.stgit@noble.brown Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: NeilBrown <neilb@suse.de> Tested-by: David Howells <dhowells@redhat.com> Tested-by: Geert Uytterhoeven <geert+renesas@glider.be> Cc: Hugh Dickins <hughd@google.com> Cc: Mel Gorman <mgorman@techsingularity.net> Cc: Trond Myklebust <trond.myklebust@hammerspace.com> Cc: Miaohe Lin <linmiaohe@huawei.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-05-03loop: remove a spurious clear of discard_alignmentChristoph Hellwig1-1/+0
The loop driver never sets a discard_alignment, so it also doens't need to clear it to zero. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Damien Le Moal <damien.lemoal@opensource.wdc.com> Reviewed-by: Chaitanya Kulkarni <kch@nvidia.com> Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com> Link: https://lore.kernel.org/r/20220418045314.360785-9-hch@lst.de Signed-off-by: Jens Axboe <axboe@kernel.dk>
2022-05-02blk-cgroup: replace bio_blkcg with bio_blkcg_cssChristoph Hellwig1-5/+7
All callers of bio_blkcg actually want the CSS, so replace it with an interface that does return the CSS. This now allows to move struct blkcg_gq to block/blk-cgroup.h instead of exposing it in a public header. Signed-off-by: Christoph Hellwig <hch@lst.de> Acked-by: Tejun Heo <tj@kernel.org> Link: https://lore.kernel.org/r/20220420042723.1010598-10-hch@lst.de Signed-off-by: Jens Axboe <axboe@kernel.dk>
2022-04-18loop: don't destroy lo->workqueue in __loop_clr_fdChristoph Hellwig1-13/+13
There is no need to destroy the workqueue when clearing unbinding a loop device from a backing file. Not doing so on the other hand avoid creating a complex lock dependency chain involving the global system_transition_mutex. Based on a patch from Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>. Reported-by: syzbot+6479585dfd4dedd3f7e1@syzkaller.appspotmail.com Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Jan Kara <jack@suse.cz> Tested-by: syzbot+6479585dfd4dedd3f7e1@syzkaller.appspotmail.com Link: https://lore.kernel.org/r/20220330052917.2566582-16-hch@lst.de Signed-off-by: Jens Axboe <axboe@kernel.dk>
2022-04-18loop: remove lo_refcount and avoid lo_mutex in ->open / ->releaseChristoph Hellwig1-30/+7
lo_refcount counts how many openers a loop device has, but that count is already provided by the block layer in the bd_openers field of the whole-disk block_device. Remove lo_refcount and allow opens to succeed even on devices beeing deleted - now that ->free_disk is implemented we can handle that race gracefull and all I/O on it will just fail. Similarly there is a small race window now where loop_control_remove does not synchronize the delete vs the remove due do bd_openers not being under lo_mutex protection, but we can handle that just as gracefully. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Jan Kara <jack@suse.cz> Link: https://lore.kernel.org/r/20220330052917.2566582-15-hch@lst.de Signed-off-by: Jens Axboe <axboe@kernel.dk>
2022-04-18loop: avoid loop_validate_mutex/lo_mutex in ->releaseTetsuo Handa1-25/+13
Since ->release is called with disk->open_mutex held, and __loop_clr_fd() from lo_release() is called via ->release when disk_openers() == 0, we are guaranteed that "struct file" which will be passed to loop_validate_file() via fget() cannot be the loop device __loop_clr_fd(lo, true) will clear. Thus, there is no need to hold loop_validate_mutex from __loop_clr_fd() if release == true. When I made commit 3ce6e1f662a91097 ("loop: reintroduce global lock for safe loop_validate_file() traversal"), I wrote "It is acceptable for loop_validate_file() to succeed, for actual clear operation has not started yet.". But now I came to feel why it is acceptable to succeed. It seems that the loop driver was added in Linux 1.3.68, and if (lo->lo_refcnt > 1) return -EBUSY; check in loop_clr_fd() was there from the beginning. The intent of this check was unclear. But now I think that current disk_openers(lo->lo_disk) > 1 form is there for three reasons. (1) Avoid I/O errors when some process which opens and reads from this loop device in response to uevent notification (e.g. systemd-udevd), as described in commit a1ecac3b0656a682 ("loop: Make explicit loop device destruction lazy"). This opener is short-lived because it is likely that the file descriptor used by that process is closed soon. (2) Avoid I/O errors caused by underlying layer of stacked loop devices (i.e. ioctl(some_loop_fd, LOOP_SET_FD, other_loop_fd)) being suddenly disappeared. This opener is long-lived because this reference is associated with not a file descriptor but lo->lo_backing_file. (3) Avoid I/O errors caused by underlying layer of mounted loop device (i.e. mount(some_loop_device, some_mount_point)) being suddenly disappeared. This opener is long-lived because this reference is associated with not a file descriptor but mount. While race in (1) might be acceptable, (2) and (3) should be checked racelessly. That is, make sure that __loop_clr_fd() will not run if loop_validate_file() succeeds, by doing refcount check with global lock held when explicit loop device destruction is requested. As a result of no longer waiting for lo->lo_mutex after setting Lo_rundown, we can remove pointless BUG_ON(lo->lo_state != Lo_rundown) check. Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp> Signed-off-by: Christoph Hellwig <hch@lst.de> Link: https://lore.kernel.org/r/20220330052917.2566582-14-hch@lst.de Signed-off-by: Jens Axboe <axboe@kernel.dk>
2022-04-18loop: suppress uevents while reconfiguring the deviceChristoph Hellwig1-4/+21
Currently, udev change event is generated for a loop device before the device is ready for IO. Due to serialization on lo->lo_mutex in lo_open() this does not matter because anybody is able to open the device and do IO only after the configuration is finished. However this synchronization in lo_open() is going away so make sure userspace reacting to the change event will see the new device state by generating the event only when the device is setup. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Jan Kara <jack@suse.cz> Link: https://lore.kernel.org/r/20220330052917.2566582-13-hch@lst.de Signed-off-by: Jens Axboe <axboe@kernel.dk>
2022-04-18loop: implement ->free_diskChristoph Hellwig1-4/+12
Ensure that the lo_device which is stored in the gendisk private data is valid until the gendisk is freed. Currently the loop driver uses a lot of effort to make sure a device is not freed when it is still in use, but to to fix a potential deadlock this will be relaxed a bit soon. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Jan Kara <jack@suse.cz> Link: https://lore.kernel.org/r/20220330052917.2566582-12-hch@lst.de Signed-off-by: Jens Axboe <axboe@kernel.dk>
2022-04-18loop: only freeze the queue in __loop_clr_fd when neededChristoph Hellwig1-3/+9
->release is only called after all outstanding I/O has completed, so only freeze the queue when clearing the backing file of a live loop device. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Jan Kara <jack@suse.cz> Tested-by: Darrick J. Wong <djwong@kernel.org> Link: https://lore.kernel.org/r/20220330052917.2566582-11-hch@lst.de Signed-off-by: Jens Axboe <axboe@kernel.dk>
2022-04-18loop: don't freeze the queue in lo_releaseChristoph Hellwig1-7/+0
By the time the final ->release is called there can't be outstanding I/O. For non-final ->release there is no need for driver action at all. Thus remove the useless queue freeze. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Jan Kara <jack@suse.cz> Tested-by: Darrick J. Wong <djwong@kernel.org> Link: https://lore.kernel.org/r/20220330052917.2566582-10-hch@lst.de Signed-off-by: Jens Axboe <axboe@kernel.dk>
2022-04-18loop: remove the racy bd_inode->i_mapping->nrpages assertsChristoph Hellwig1-20/+0
Nothing prevents a file system or userspace opener of the block device from redirtying the page right afte sync_blockdev returned. Fortunately data in the page cache during a block device change is mostly harmless anyway. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Jan Kara <jack@suse.cz> Tested-by: Darrick J. Wong <djwong@kernel.org> Link: https://lore.kernel.org/r/20220330052917.2566582-9-hch@lst.de Signed-off-by: Jens Axboe <axboe@kernel.dk>
2022-04-18loop: initialize the worker tracking fields onceChristoph Hellwig1-4/+3
There is no need to reinitialize idle_worker_list, worker_tree and timer every time a loop device is configured. Just initialize them once at allocation time. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Jan Kara <jack@suse.cz> Reviewed-by: Chaitanya Kulkarni <kch@nvidia.com> Tested-by: Darrick J. Wong <djwong@kernel.org> Link: https://lore.kernel.org/r/20220330052917.2566582-8-hch@lst.de Signed-off-by: Jens Axboe <axboe@kernel.dk>
2022-04-18loop: de-duplicate the idle worker freeing codeChristoph Hellwig1-38/+35
Use a common helper for both timer based and uncoditional freeing of idle workers. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Jan Kara <jack@suse.cz> Tested-by: Darrick J. Wong <djwong@kernel.org> Link: https://lore.kernel.org/r/20220330052917.2566582-7-hch@lst.de Signed-off-by: Jens Axboe <axboe@kernel.dk>
2022-04-18block: add a bdev_discard_granularity helperChristoph Hellwig1-1/+1
Abstract away implementation details from file systems by providing a block_device based helper to retrieve the discard granularity. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com> Acked-by: Christoph Böhmwalder <christoph.boehmwalder@linbit.com> [drbd] Acked-by: Ryusuke Konishi <konishi.ryusuke@gmail.com> Acked-by: David Sterba <dsterba@suse.com> [btrfs] Link: https://lore.kernel.org/r/20220415045258.199825-26-hch@lst.de Signed-off-by: Jens Axboe <axboe@kernel.dk>
2022-04-18block: remove QUEUE_FLAG_DISCARDChristoph Hellwig1-8/+3
Just use a non-zero max_discard_sectors as an indicator for discard support, similar to what is done for write zeroes. The only places where needs special attention is the RAID5 driver, which must clear discard support for security reasons by default, even if the default stacking rules would allow for it. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com> Acked-by: Christoph Böhmwalder <christoph.boehmwalder@linbit.com> [drbd] Acked-by: Jan Höppner <hoeppner@linux.ibm.com> [s390] Acked-by: Coly Li <colyli@suse.de> [bcache] Acked-by: David Sterba <dsterba@suse.com> [btrfs] Reviewed-by: Chaitanya Kulkarni <kch@nvidia.com> Link: https://lore.kernel.org/r/20220415045258.199825-25-hch@lst.de Signed-off-by: Jens Axboe <axboe@kernel.dk>
2022-04-18block: add a bdev_nonrot helperChristoph Hellwig1-1/+1
Add a helper to check the nonrot flag based on the block_device instead of having to poke into the block layer internal request_queue. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com> Acked-by: David Sterba <dsterba@suse.com> [btrfs] Reviewed-by: Chaitanya Kulkarni <kch@nvidia.com> Link: https://lore.kernel.org/r/20220415045258.199825-12-hch@lst.de Signed-off-by: Jens Axboe <axboe@kernel.dk>
2022-04-02Merge tag 'for-5.18/drivers-2022-04-01' of git://git.kernel.dk/linux-blockLinus Torvalds1-0/+1
Pull block driver fixes from Jens Axboe: "Followup block driver updates and fixes for the 5.18-rc1 merge window. In detail: - NVMe pull request - Fix multipath hang when disk goes live over reconnect (Anton Eidelman) - fix RCU hole that allowed for endless looping in multipath round robin (Chris Leech) - remove redundant assignment after left shift (Colin Ian King) - add quirks for Samsung X5 SSDs (Monish Kumar R) - fix the read-only state for zoned namespaces with unsupposed features (Pankaj Raghav) - use a private workqueue instead of the system workqueue in nvmet (Sagi Grimberg) - allow duplicate NSIDs for private namespaces (Sungup Moon) - expose use_threaded_interrupts read-only in sysfs (Xin Hao)" - nbd minor allocation fix (Zhang) - drbd fixes and maintainer addition (Lars, Jakob, Christoph) - n64cart build fix (Jackie) - loop compat ioctl fix (Carlos) - misc fixes (Colin, Dongli)" * tag 'for-5.18/drivers-2022-04-01' of git://git.kernel.dk/linux-block: drbd: remove check of list iterator against head past the loop body drbd: remove usage of list iterator variable after loop nbd: fix possible overflow on 'first_minor' in nbd_dev_add() MAINTAINERS: add drbd co-maintainer drbd: fix potential silent data corruption loop: fix ioctl calls using compat_loop_info nvme-multipath: fix hang when disk goes live over reconnect nvme: fix RCU hole that allowed for endless looping in multipath round robin nvme: allow duplicate NSIDs for private namespaces nvmet: remove redundant assignment after left shift nvmet: use a private workqueue instead of the system workqueue nvme-pci: add quirks for Samsung X5 SSDs nvme-pci: expose use_threaded_interrupts read-only in sysfs nvme: fix the read-only state for zoned namespaces with unsupposed features n64cart: convert bi_disk to bi_bdev->bd_disk fix build xen/blkfront: fix comment for need_copy xen-blkback: remove redundant assignment to variable i
2022-03-30loop: fix ioctl calls using compat_loop_infoCarlos Llamas1-0/+1
Support for cryptoloop was deleted in commit 47e9624616c8 ("block: remove support for cryptoloop and the xor transfer"), making the usage of loop_info->lo_encrypt_type obsolete. However, this member was also removed from the compat_loop_info definition and this breaks userspace ioctl calls for 32-bit binaries and CONFIG_COMPAT=y. This patch restores the compat_loop_info->lo_encrypt_type member and marks it obsolete as well as in the uapi header definitions. Fixes: 47e9624616c8 ("block: remove support for cryptoloop and the xor transfer") Signed-off-by: Carlos Llamas <cmllamas@google.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Link: https://lore.kernel.org/r/20220329201815.1347500-1-cmllamas@google.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
2022-03-22Merge tag 'for-5.18/drivers-2022-03-18' of git://git.kernel.dk/linux-blockLinus Torvalds1-12/+30
Pull block driver updates from Jens Axboe: - NVMe updates via Christoph: - add vectored-io support for user-passthrough (Kanchan Joshi) - add verbose error logging (Alan Adamson) - support buffered I/O on block devices in nvmet (Chaitanya Kulkarni) - central discovery controller support (Martin Belanger) - fix and extended the globally unique idenfier validation (Christoph) - move away from the deprecated IDA APIs (Sagi Grimberg) - misc code cleanup (Keith Busch, Max Gurtovoy, Qinghua Jin, Chaitanya Kulkarni) - add lockdep annotations for in-kernel sockets (Chris Leech) - use vmalloc for ANA log buffer (Hannes Reinecke) - kerneldoc fixes (Chaitanya Kulkarni) - cleanups (Guoqing Jiang, Chaitanya Kulkarni, Christoph) - warn about shared namespaces without multipathing (Christoph) - MD updates via Song with a set of cleanups (Christoph, Mariusz, Paul, Erik, Dirk) - loop cleanups and queue depth configuration (Chaitanya) - null_blk cleanups and fixes (Chaitanya) - Use descriptive init/exit names in virtio_blk (Randy) - Use bvec_kmap_local() in drivers (Christoph) - bcache fixes (Mingzhe) - xen blk-front persistent grant speedups (Juergen) - rnbd fix and cleanup (Gioh) - Misc fixes (Christophe, Colin) * tag 'for-5.18/drivers-2022-03-18' of git://git.kernel.dk/linux-block: (76 commits) virtio_blk: eliminate anonymous module_init & module_exit nvme: warn about shared namespaces without CONFIG_NVME_MULTIPATH nvme: remove nvme_alloc_request and nvme_alloc_request_qid nvme: cleanup how disk->disk_name is assigned nvmet: move the call to nvmet_ns_changed out of nvmet_ns_revalidate nvmet: use snprintf() with PAGE_SIZE in configfs nvmet: don't fold lines nvmet-rdma: fix kernel-doc warning for nvmet_rdma_device_removal nvmet-fc: fix kernel-doc warning for nvmet_fc_unregister_targetport nvmet-fc: fix kernel-doc warning for nvmet_fc_register_targetport nvme-tcp: lockdep: annotate in-kernel sockets nvme-tcp: don't fold the line nvme-tcp: don't initialize ret variable nvme-multipath: call bio_io_error in nvme_ns_head_submit_bio nvme-multipath: use vmalloc for ANA log buffer xen/blkfront: speed up purge_persistent_grants() raid5: initialize the stripe_head embeeded bios as needed raid5-cache: statically allocate the recovery ra bio raid5-cache: fully initialize flush_bio when needed raid5-ppl: fully initialize the bio in ppl_new_iounit ...
2022-03-16nvme: warn about shared namespaces without CONFIG_NVME_MULTIPATHChristoph Hellwig1-0/+1
Start warning about exposing a namespace as multiple block devices, and set a fixed deprecation release. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Keith Busch <kbusch@kernel.org>
2022-02-28loop: allow user to set the queue depthChaitanya Kulkarni1-1/+20
Instead of hardcoding queue depth allow user to set the hw queue depth using module parameter. Set default value to 128 to retain the existing behavior. Signed-off-by: Chaitanya Kulkarni <kch@nvidia.com> Reviewed-by: Himanshu Madhani <himanshu.madhani@oracle.com> Link: https://lore.kernel.org/r/20220215213310.7264-5-kch@nvidia.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
2022-02-28loop: remove extra variable in lo_req_flushChaitanya Kulkarni1-2/+1
The local variable file is used to pass it to the vfs_fsync(). We can get away with using lo->lo_backing_file instead of storing in a local variable which is not used anywhere else. No functional change in this patch. Signed-off-by: Chaitanya Kulkarni <kch@nvidia.com> Reviewed-by: Himanshu Madhani <himanshu.madhani@oracle.com> Link: https://lore.kernel.org/r/20220215213310.7264-4-kch@nvidia.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
2022-02-28loop: remove extra variable in lo_fallocate()Chaitanya Kulkarni1-2/+1
The local variable q is used to pass it to the blk_queue_discard(). We can get away with using lo->lo_queue instead of storing in a local variable which is not used anywhere else. No functional change in this patch. Signed-off-by: Chaitanya Kulkarni <kch@nvidia.com> Reviewed-by: Himanshu Madhani <himanshu.madhani@oracle.com> Link: https://lore.kernel.org/r/20220215213310.7264-3-kch@nvidia.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
2022-02-28loop: use sysfs_emit() in the sysfs xxx show()Chaitanya Kulkarni1-5/+5
sprintf does not know the PAGE_SIZE maximum of the temporary buffer used for outputting sysfs content and it's possible to overrun the PAGE_SIZE buffer length. Use a generic sysfs_emit function that knows the size of the temporary buffer and ensures that no overrun is done for offset attribute in loop_attr_[offset|sizelimit|autoclear|partscan|dio]_show() callbacks. Signed-off-by: Chaitanya Kulkarni <kch@nvidia.com> Reviewed-by: Himanshu Madhani <himanshu.madhani@oracle.com> Link: https://lore.kernel.org/r/20220215213310.7264-2-kch@nvidia.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
2022-02-28loop: clean up grammar in warning messageColin Ian King1-2/+2
The phrase "has still" should be "still has" to clean up the grammar. Signed-off-by: Colin Ian King <colin.i.king@gmail.com> Link: https://lore.kernel.org/r/20220208114656.61629-1-colin.i.king@gmail.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
2022-02-12block: loop:use kstatfs.f_bsize of backing file to set discard granularityMing Lei1-1/+7
If backing file's filesystem has implemented ->fallocate(), we think the loop device can support discard, then pass sb->s_blocksize as discard_granularity. However, some underlying FS, such as overlayfs, doesn't set sb->s_blocksize, and causes discard_granularity to be set as zero, then the warning in __blkdev_issue_discard() is triggered. Christoph suggested to pass kstatfs.f_bsize as discard granularity, and this way is fine because kstatfs.f_bsize means 'Optimal transfer block size', which still matches with definition of discard granularity. So fix the issue by setting discard_granularity as kstatfs.f_bsize if it is available, otherwise claims discard isn't supported. Cc: Christoph Hellwig <hch@lst.de> Cc: Vivek Goyal <vgoyal@redhat.com> Reported-by: Pei Zhang <pezhang@redhat.com> Signed-off-by: Ming Lei <ming.lei@redhat.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Link: https://lore.kernel.org/r/20220126035830.296465-1-ming.lei@redhat.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
2022-02-11loop: revert "make autoclear operation asynchronous"Tetsuo Handa1-36/+29
The kernel test robot is reporting that xfstest which does umount ext2 on xfs umount xfs sequence started failing, for commit 322c4293ecc58110 ("loop: make autoclear operation asynchronous") removed a guarantee that fput() of backing file is processed before lo_release() from close() returns to user mode. And syzbot is reporting that deferring destroy_workqueue() from __loop_clr_fd() to a WQ context did not help [1]. Revert that commit. Link: https://syzkaller.appspot.com/bug?extid=831661966588c802aae9 [1] Reported-by: kernel test robot <oliver.sang@intel.com> Acked-by: Jan Kara <jack@suse.cz> Reviewed-by: Christoph Hellwig <hch@lst.de> Reported-by: syzbot <syzbot+831661966588c802aae9@syzkaller.appspotmail.com> Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp> Link: https://lore.kernel.org/r/20220211071554.3424-1-penguin-kernel@I-love.SAKURA.ne.jp Signed-off-by: Jens Axboe <axboe@kernel.dk>
2022-01-13loop: remove redundant initialization of pointer nodeColin Ian King1-1/+1
The pointer node is being initialized with a value that is never read, it is being re-assigned the same value a little futher on. Remove the redundant initialization. Cleans up clang scan warning: drivers/block/loop.c:823:19: warning: Value stored to 'node' during its initialization is never read [deadcode.DeadStores] Signed-off-by: Colin Ian King <colin.i.king@gmail.com> Link: https://lore.kernel.org/r/20220113001432.1331871-1-colin.i.king@gmail.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
2022-01-12Merge tag 'for-5.17/drivers-2022-01-11' of git://git.kernel.dk/linux-blockLinus Torvalds1-56/+52
Pull block driver updates from Jens Axboe: - mtip32xx pci cleanups (Bjorn) - mtip32xx conversion to generic power management (Vaibhav) - rsxx pci powermanagement cleanups (Bjorn) - Remove the rsxx driver. This hardware never saw much adoption, and it's been end of lifed for a while. (Christoph) - MD pull request from Song: - REQ_NOWAIT support (Vishal Verma) - raid6 benchmark optimization (Dirk Müller) - Fix for acct bioset (Xiao Ni) - Clean up max_queued_requests (Mariusz Tkaczyk) - PREEMPT_RT optimization (Davidlohr Bueso) - Use default_groups in kobj_type (Greg Kroah-Hartman) - Use attribute groups in pktcdvd and rnbd (Greg) - NVMe pull request from Christoph: - increment request genctr on completion (Keith Busch, Geliang Tang) - add a 'iopolicy' module parameter (Hannes Reinecke) - print out valid arguments when reading from /dev/nvme-fabrics (Hannes Reinecke) - Use struct_group() in drbd (Kees) - null_blk fixes (Ming) - Get rid of congestion logic in pktcdvd (Neil) - Floppy ejection hang fix (Tasos) - Floppy max user request size fix (Xiongwei) - Loop locking fix (Tetsuo) * tag 'for-5.17/drivers-2022-01-11' of git://git.kernel.dk/linux-block: (32 commits) md: use default_groups in kobj_type md: Move alloc/free acct bioset in to personality lib/raid6: Use strict priority ranking for pq gen() benchmarking lib/raid6: skip benchmark of non-chosen xor_syndrome functions md: fix spelling of "its" md: raid456 add nowait support md: raid10 add nowait support md: raid1 add nowait support md: add support for REQ_NOWAIT md: drop queue limitation for RAID1 and RAID10 md/raid5: play nice with PREEMPT_RT block/rnbd-clt-sysfs: use default_groups in kobj_type pktcdvd: convert to use attribute groups block: null_blk: only set set->nr_maps as 3 if active poll_queues is > 0 nvme: add 'iopolicy' module parameter nvme: drop unused variable ctrl in nvme_setup_cmd nvme: increment request genctr on completion nvme-fabrics: print out valid arguments when reading from /dev/nvme-fabrics block: remove the rsxx driver rsxx: Drop PCI legacy power management ...
2022-01-12Merge tag 'for-5.17/block-2022-01-11' of git://git.kernel.dk/linux-blockLinus Torvalds1-5/+4
Pull block updates from Jens Axboe: - Unify where the struct request handling code is located in the blk-mq code (Christoph) - Header cleanups (Christoph) - Clean up the io_context handling code (Christoph, me) - Get rid of ->rq_disk in struct request (Christoph) - Error handling fix for add_disk() (Christoph) - request allocation cleanusp (Christoph) - Documentation updates (Eric, Matthew) - Remove trivial crypto unregister helper (Eric) - Reduce shared tag overhead (John) - Reduce poll_stats memory overhead (me) - Known indirect function call for dio (me) - Use atomic references for struct request (me) - Support request list issue for block and NVMe (me) - Improve queue dispatch pinning (Ming) - Improve the direct list issue code (Keith) - BFQ improvements (Jan) - Direct completion helper and use it in mmc block (Sebastian) - Use raw spinlock for the blktrace code (Wander) - fsync error handling fix (Ye) - Various fixes and cleanups (Lukas, Randy, Yang, Tetsuo, Ming, me) * tag 'for-5.17/block-2022-01-11' of git://git.kernel.dk/linux-block: (132 commits) MAINTAINERS: add entries for block layer documentation docs: block: remove queue-sysfs.rst docs: sysfs-block: document virt_boundary_mask docs: sysfs-block: document stable_writes docs: sysfs-block: fill in missing documentation from queue-sysfs.rst docs: sysfs-block: add contact for nomerges docs: sysfs-block: sort alphabetically docs: sysfs-block: move to stable directory block: don't protect submit_bio_checks by q_usage_counter block: fix old-style declaration nvme-pci: fix queue_rqs list splitting block: introduce rq_list_move block: introduce rq_list_for_each_safe macro block: move rq_list macros to blk-mq.h block: drop needless assignment in set_task_ioprio() block: remove unnecessary trailing '\' bio.h: fix kernel-doc warnings block: check minor range in device_add_disk() block: use "unsigned long" for blk_validate_block_size(). block: fix error unwinding in device_add_disk ...
2021-12-13loop: make autoclear operation asynchronousTetsuo Handa1-29/+36
syzbot is reporting circular locking problem at __loop_clr_fd() [1], for commit 87579e9b7d8dc36e ("loop: use worker per cgroup instead of kworker") is calling destroy_workqueue() with disk->open_mutex held. This circular dependency cannot be broken unless we call __loop_clr_fd() without holding disk->open_mutex. Therefore, defer __loop_clr_fd() from lo_release() to a WQ context. Link: https://syzkaller.appspot.com/bug?extid=643e4ce4b6ad1347d372 [1] Reported-by: syzbot <syzbot+643e4ce4b6ad1347d372@syzkaller.appspotmail.com> Suggested-by: Christoph Hellwig <hch@infradead.org> Cc: Jan Kara <jack@suse.cz> Tested-by: syzbot+643e4ce4b6ad1347d372@syzkaller.appspotmail.com Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp> Reviewed-by: Christoph Hellwig <hch@lst.de> Link: https://lore.kernel.org/r/1ed7df28-ebd6-71fb-70e5-1c2972e05ddb@i-love.sakura.ne.jp Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-11-29loop: Use pr_warn_once() for loop_control_remove() warningTetsuo Handa1-1/+1
kernel test robot reported that RCU stall via printk() flooding is possible [1] when stress testing. Link: https://lkml.kernel.org/r/20211129073709.GA18483@xsang-OptiPlex-9020 [1] Reported-by: kernel test robot <oliver.sang@intel.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-11-29loop: don't hold lo_mutex during __loop_clr_fd()Tetsuo Handa1-33/+22
syzbot is reporting circular locking problem at __loop_clr_fd() [1], for commit 87579e9b7d8dc36e ("loop: use worker per cgroup instead of kworker") is calling destroy_workqueue() with lo->lo_mutex held. Since all functions where lo->lo_state matters are already checking lo->lo_state with lo->lo_mutex held (in order to avoid racing with e.g. ioctl(LOOP_CTL_REMOVE)), and __loop_clr_fd() can be called from either ioctl(LOOP_CLR_FD) xor close(), lo->lo_state == Lo_rundown is considered as an exclusive lock for __loop_clr_fd(). Therefore, hold lo->lo_mutex inside __loop_clr_fd() only when asserting/updating lo->lo_state. Since ioctl(LOOP_CLR_FD) depends on lo->lo_state == Lo_bound, a valid lo->lo_backing_file must have been assigned by ioctl(LOOP_SET_FD) or ioctl(LOOP_CONFIGURE). Thus, we can remove lo->lo_backing_file test, and convert __loop_clr_fd() into a void function. Link: https://syzkaller.appspot.com/bug?extid=63614029dfb79abd4383 [1] Reported-by: syzbot <syzbot+63614029dfb79abd4383@syzkaller.appspotmail.com> Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp> Reviewed-by: Christoph Hellwig <hch@lst.de> Link: https://lore.kernel.org/r/8ebe3b2e-8975-7f26-0620-7144a3b8b8cd@i-love.sakura.ne.jp Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-11-29block: remove GENHD_FL_EXT_DEVTChristoph Hellwig1-1/+0
All modern drivers can support extra partitions using the extended dev_t. In fact except for the ioctl method drivers never even see partitions in normal operation. So remove the GENHD_FL_EXT_DEVT and allow extra partitions for all block devices that do support partitions, and require those that do not support partitions to explicit disallow them using GENHD_FL_NO_PART. Signed-off-by: Christoph Hellwig <hch@lst.de> Link: https://lore.kernel.org/r/20211122130625.1136848-12-hch@lst.de Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-11-29block: rename GENHD_FL_NO_PART_SCAN to GENHD_FL_NO_PARTChristoph Hellwig1-4/+4
The GENHD_FL_NO_PART_SCAN controls more than just partitions canning, so rename it to GENHD_FL_NO_PART. Signed-off-by: Christoph Hellwig <hch@lst.de> Acked-by: Ulf Hansson <ulf.hansson@linaro.org> Link: https://lore.kernel.org/r/20211122130625.1136848-7-hch@lst.de Signed-off-by: Jens Axboe <axboe@kernel.dk>
generated by cgit v1.2.3 (git 2.39.0) at 2024-12-03 15:59:14 +0300